extensor
/ɪkˈstensə(r)/(亦作extensor muscle)
noun
1- Anatomy a muscle whose contraction extends or straightens a limb or other part of the body【剖】伸肌。常与FLEXOR相对。
1.1
- any of a number of specific muscles in the arm, hand, leg, and foot（臂、手、腿和脚的）…（伸）肌。
词源
early 18th cent.: from late Latin, from extens- 'stretched out', from the verb extendere （see EXTEND）.